If you don't need a CMOY, build one anyway, you'll spend $15 on parts and keep the opamp for later. :)

I agree on the CMOY. If you arrange and populate your own breadboard it gives you experience translating an abstract circuit diagram into a physical working circuit ...and it is simple enough that troubleshooting won't be too bad if necessary.

In theory you could learn more from the Mini3, but I think most DIYers prefer a more hands on approach to learning (I know I do).

You might want to start with a CMoy. Once you understand that, you can move onto bigger projects.

I'm planning to build a three channel Beta22. I have some of the parts, but think it'll run me about $800, including raw aluminum for the case I'll build from scratch.

I'm just curious, but people make the task sound very complicated. Is this based on the assumption that someone is starting from scratch -- not knowing basic electronics, never having read schematics or done any soldering?

Or do you guys do projects using basic protoboards instead of the printed boards available at AMB, so component layout has to be factored in?

When you've worked on protoboard, read schematics and did layouts, you can debug PCBs quite easily. If you've done nothing but stuff PCBs off a parts list with nicely labelled parts, the chances that you can find a fault is considerably lower. I started off with a Pimeta, wasn't too bad, but I burned an opamp and had a hard time figuring it out. Even after, I still couldn't build a CMOY properly. It took a few weeks of reading before I finally was able to make sense of the schematic and layout of a CMOY to know what is there, why it's there and most importantly, what it's doing. Every amp built afterwards has been MUCH easier since.

radioactive28, it's not as hard as a lot of people make it out to be. People see a schematic or a little math, then throw up their hands and say that they're not good at this sort of thing. But a schematic is really not that hard to read and once you build or repair a few things, you begin to see how it all goes together.

For most solid state stuff, I just get the boards and stuff them. It's pretty straightforward. For tube gear, I pick up individual solder turrets at a local place and mount those on aluminum panels. You have to do your own layout, but it isn't that bad. You mostly want to keep the circuit path as short as possible.

radioactive28, it's not as hard as a lot of people make it out to be. People see a schematic or a little math, then throw up their hands and say that they're not good at this sort of thing. But a schematic is really not that hard to read and once you build or repair a few things, you begin to see how it all goes together.

Ah, right, thanks for the clarification. See this quite often, and I think the only thing these people aren't good at is trying. Haven't gotten my feet all that wet in doing electronics and amps, but learning the science was quite a long journey.